The reference was to a prisoner at Magdeburg who received a book which contained messages written on the flyleaves in lemon juice. He held the book to the fire and by doing this the written words came out in brown lines and could be read. Lafayette took the hint, and discovered the message written with this invisible ink on the bit of paper. After this Bollman was allowed to lend Lafayette a book to read. It came back with lemon-juice messages on its margins. Lafayette wrote that he was sometimes allowed to drive, and as he was unknown to Bollman, he suggested a signal by which he could be recognized. He said that his lieutenant was a sheepish dolt, and that his corporal was covetous, treacherous, and cowardly. He added that the rides were allowed for the sake of his health. It appears that the government did not wish to arouse the frenzy of indignation that would follow if Lafayette were allowed to die in prison, so he was occasionally taken out to ride a league or even two from the fortress gate. If a rescuer and a trusty helper should appear, they could surely effect the escape. Lafayette would agree to frighten the cowardly little corporal himself; they need not provide a sword for him, for he would take the corporal's. An extra horse, one or two horses along the road--it could easily be done. It was a bold plan, but the bolder the plan, the more unexpected it was, and the better chance of success. Every day he would watch for them along the road. After securing this definite information, the doctor retired to Vienna to make further plans. This account may be in some respects the later elaboration of a story many times retold. But it sounds probable. At any rate, in some such way Dr. Bollman gained communication with Lafayette's cell, and brought the welcome news that friends were working for him. Then they projected a plan. The story is again taken up in a coffeehouse in Vienna where Bollman is accustomed to go. Lafayette has suggested an assistant, and Bollman realizes that he can do nothing without one. Therefore he is looking about to find one who shall have spirit and fitness for the work. We see him now at the supper table, eagerly conversing with a certain young American, like himself a medical student on his travels. Curiously enough, it is Francis Kinloch Huger, now twenty-one years old. They talk of America. Bollman, with elaborate inadvertence, touches on the personality of Lafayette. The young man relates his childish memory of the arrival of that enthusiastic youth when he first came ashore at his father's South Carolina country place. Bollman tests Huger in various ways and makes up his mind that this is the best possible person to help him. He broaches the subject. Young Huger is only too ready--this very enterprise has been his dearest thought and his dream. The danger does not daunt him. "He did not let the grass grow under his feet," said his daughter years later, "but accepted at once."